When Atari first developed Pong -- the first commercially successful video arcade game ever -- it was never even intended to be sold.
The original Pong prototype was created by Atari engineer Allan Alcorn strictly as a training exercise. When Alcorn was hired by Atari, he had never developed anything like a video game before, so Bushnell secretly assigned Alcorn the task of developing a rough clone of the table tennis simulator made successful on the Magnavox Odyssey home game console. Bushnell told Alcorn there was an actual customer -- General Electric -- for the product, but Bushnell never intended to sell the game that would become Pong. It was simply there to get Alcorn familiar with building video games.
Alcorn over-delivered, creating a relatively advanced game that allowed players to influence the angle of their volleys based on where the pixel-ball struck their simulated paddles. Bushnell had promised Bally a driving simulator, but Alcorn's Pong looked so good that Bushnell tried to substitute Pong as the game that would fulfill the contract. To prove how viable Pong would be, Bushnell had the first prototype installed at Andy Capp's Tavern in Menlo Park, CA. The game quickly malfunctioned -- because it was overstuffed with quarters. Customers couldn't get enough.
Bushnell then had to backtrack and talk Bally (and then Midway) out of wanting Pong, so Atari could distribute the hit game itself. That was a smart move, as the success of Pong exploded over the next few years and was the foundation of Atari's success.
Not bad for a training exercise.
That's not just some accidentally amazing business acumen; it's a viability-verifying volley of video game Geek Trivia.